The goal of this project is to identify genetic factors contributing to noninsulin dependent diabetes (NIDDM) and its' complications by developing a national registry of well studied families. Families are identified in which 2 siblings have NIDDM and additional siblings and/or living parents are available for study. The lymphoblastoid cell lines and data will be made available to investigators who are studying the genetic basis of NIDDM. This project is continuing for its third year, with the expectation of a fourth year as well. Locally, approximately 40 families have been studied to date.